Need some math help please!!!

4 out of 10 adults in a certain city buy their drugs at large drug stores. if this city has 34,000 adults, how many of these adults would you expect to buy their drugs at large drug stores?

Thanks in advance.

4/10 = 40%, so you would also expect 40% of the 34,000 adults to buy their drugs at large drug stores. 40% of 34,000 is equal to 0.40 * 34,000 = 13,600.

Another way to do the problem is to set up a relationship with an unknown variable:
4/10 = x/34,000

then cross-multiply, giving:
10x = 136,000

dividing both sides by 10 gives:
x = 13,600

Hope this helps!

Think of it this way, it tells you that out of your whole 10 adults, you have 4 people who will buy their drugs at the large stores. so for every 10 you have 4, this can be more conveniently written as a fraction in the form of Part/Whole, or in this case 4/10.

** In some classes, you are told to refer to this as a ratio**

So now, using proportions, we see that Part/whole = part/whole provided the two are proportional.
4/10=x/34000

Now, just isolate x and you see you need
34000*(4/10) = x

This will tell you x, the number of people out of the 34000 that will buy their drugs at the large drug stores.

4/10 = .4

.4(34000) or (4/10)(34000) = 4(3400) = 13600 adults